mighty good reason for it."

"Of course. Every lunatic has loads of good reasons for anything
he does," muttered Eph.

"Look here, fellows!" ordered Jack Benson, almost staggering as
he approached them.

"Great Dewey! Am I going crazy, too?" muttered Eph, staring hard.
"What I think I see in Jack's hands are some of the missing copper
plates."

"It's exactly what you do see," announced Jack Benson, his face
beaming.

"But how---"

"How they came to be there I don't know," Benson replied. "But
when I threw away your quarter, Eph, it rolled under the bench.
There wasn't supposed to be anything metallic under the bench,
but I felt almost, sure that I had heard the silver strike against
something metallic. Even then it seemed like a crazy notion to
me. I didn't really expect to find anything, but some uncontrollable
impulse urged me to go hustling under the bench. And so I found
these duplicate plates, wedged in behind a lot of junk and right
up against the partition."

Hal Hastings, in the meantime, had taken one of the plates from
Lieutenant Jack's hand, and was now quietly fitting it where it
belonged on the motor.

The six midshipmen, as soon as they realized what had happened,
had sprung eagerly to the door of the engine room and stood peering
in. Behind them were the cook and crew of the "Dodger."

Presently Hal straightened up.

"Sir," he said gravely, "I have hopes that if you test the compressed
air apparatus you will find that this motor will do its share."

Midshipmen and crew drew back as Jack and Eph came out of the
engine room. Lieutenant Jack had his wrench in hand, and went back
to his former post.

"Young gentlemen," the commanding officer announced coolly, "we
will take up, at the point where we were interrupted, the work
of expelling the water from the compartments Are you ready, Mr.
Hastings?"

"Right by my post, sir," came from Hal.

The six midshipmen gathered about Benson with a stronger sense
of fascination than ever. Eph stepped past them to the stairs
leading---to the little conning tower.

With steady hand Jack Benson turned the wrench. The motor began
to "mote" and there was a sense of being lifted.

"Going up!" sang Ensign Eph, with a grin.

Nor could Dan Dalzell help imitating the grin and calling out
jovially:

"Let me out at the top floor, please!"

Having set the compressed air at work on the forward tanks, Jack
Benson quickly shifted the wrench, and w